CA1301754C - Process for recovering caffeine absorbed in activated carbon, and a process for decaffeinating coffee - Google Patents
Process for recovering caffeine absorbed in activated carbon, and a process for decaffeinating coffeeInfo
- Publication number
- CA1301754C CA1301754C CA000538013A CA538013A CA1301754C CA 1301754 C CA1301754 C CA 1301754C CA 000538013 A CA000538013 A CA 000538013A CA 538013 A CA538013 A CA 538013A CA 1301754 C CA1301754 C CA 1301754C
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- Prior art keywords
- caffeine
- acid
- activated carbon
- extraction
- carbon
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D473/00—Heterocyclic compounds containing purine ring systems
- C07D473/02—Heterocyclic compounds containing purine ring systems with oxygen, sulphur, or nitrogen atoms directly attached in positions 2 and 6
- C07D473/04—Heterocyclic compounds containing purine ring systems with oxygen, sulphur, or nitrogen atoms directly attached in positions 2 and 6 two oxygen atoms
- C07D473/06—Heterocyclic compounds containing purine ring systems with oxygen, sulphur, or nitrogen atoms directly attached in positions 2 and 6 two oxygen atoms with radicals containing only hydrogen and carbon atoms, attached in position 1 or 3
- C07D473/12—Heterocyclic compounds containing purine ring systems with oxygen, sulphur, or nitrogen atoms directly attached in positions 2 and 6 two oxygen atoms with radicals containing only hydrogen and carbon atoms, attached in position 1 or 3 with methyl radicals in positions 1, 3, and 7, e.g. caffeine
-
- A—HUMAN NECESSITIES
- A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
- A23F—COFFEE; TEA; THEIR SUBSTITUTES; MANUFACTURE, PREPARATION, OR INFUSION THEREOF
- A23F5/00—Coffee; Coffee substitutes; Preparations thereof
- A23F5/20—Reducing or removing alkaloid content; Preparations produced thereby; Extracts or infusions thereof
- A23F5/22—Reducing or removing alkaloid content from coffee extract
- A23F5/223—Reducing or removing alkaloid content from coffee extract using flocculating, precipitating, adsorbing or complex-forming agents, or ion-exchangers
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Polymers & Plastics (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Tea And Coffee (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
Abstract
Title: A process for recovering caffeine absorbed in activated carbon, and a process for decaffeinating coffee Abstract A process for recovering from caffeine-loaded activated carbon by treatment of the loaded carbon with an acid. According to the present invention, activated carbon is treated with a compound having the formula
Description
~3~ 7~
Title: A process for recovering caffeine absorhed in activated carbon, and a process for decaffeinatin~ coffee.
This invention relates to a process for recovering caffeine from loaded activated carbon by traatment with an acid.
In the literature much has been published on the recovery of caffeine from caffeine-loaded activated carbon using solutions of acids. East German patent 7856~
relates to the recovery of caffeine from caffeine-loaded activated carbon using more concentrated acid than hitherto usual, giving rise to a clearly better extraction than the weakly acid solutions hitherto used. European patent application 42295 (December 23, 1981) relates to the use of glacial acetic acid as a means for removing caffeine from activated carbon.
European patent application 76620 (April 13, 1983) of the same applicants indicates that glacial acetic acid has the best effect indeed, but that for security reasons it is preferred to sacrifice a part of the efficiency and to use less concentrated acetic acid solutions.
Finally, European patent application 129609 (January 2, 1985) relates to the use of formic acid or mixtures of formic acid with a slight amount of water for recovering caffeine~
According to this last publication the use of formic ~3~ i4 acid leads to considerably better extraction results than the use of acetic acid. Formic acid, however, has a number of drawbacks, in particular the high volatil-ity.
The object of the present invention is to provide a process for recovering caffeine from caffeine-loaded activated carbon, which process gives a clearly better extraction efficiency than the hitherto known, above described means, while the rate of desorption is higher.
0 Other advantages of the invention will appear from the detailed discussion of the various preferred forms.
According to the invention the process for recover-ing caffeine from caffeine-loaded activated carbon is characterized by treating the activated carbon with 15 an acid having the formula H
Rl - C - COOH
wherein R1 is methyl, H or C1 and R2 is an electron-absorbing group.
Surprisingly, it has turned out that these acids alone, or in combination with each other or with other 20 acids give excellent results in the removal of caffeine from caffeine-loaded activated carbon. Preferably, this treatment takes place in a continuous countercurrent extraction.
According to a first preferred form the caffeine--25 loaded activated carbon is treated with mono- and/or dichloroacetic acicl.
In another preferred form the invention is charac-terized by treating the activated carbon with an acid having the above formula, wherein Rl is methyl or H
and R2 is OH.
Mono- and/or dichloroacetic acid, lactic acid but also glycolic acid have proved to be particularly suitable means for recovering caffeine from activated carbon, which means give no problems with respect to roastability or volatility. Besides, it has turned out that these are excellent extracting agents leading to very high extraction efficiencies while the initial extraction is also very high, which is of special impor-tance in continuous countercurrent methods. By a very high initial extraction is meant that upon contact of caffeine-free acid with loaded activated carbon a relatively large part of the caffeine present is nearly immediately released from the activated carbon.
It will be clear that this is advantageous to a continuous countercurrent extraction because this means that the activated carbon substantially released from caffeine is subjected to a very efficient final extraction.
Moreover, a number of these acids also originally occur in coffee. This means that it is not necessary ~s tothermally regenerate the treated carbon before reusing them.
It is observed that lactic acid occurs in two ~3~7~
isomeric forms. Whether D-lactic acid, L-lactic acid or a mixture thereof is used has no effect on the present invention. So for economical reasons a racemic mlxture is preferably used.
According to a specific preferred form the acids used according to the invention may be combined with other acids, such as formic acid, acetic acid and/of propionic acid.
The process according to the invention is prefer-lo ably carried out at a temperature of more than 100C
because an efficient extraction takes place at these temperatures. It is not necessary, however, to use superatmospheric pressures, which is of course a clear advantage. The upper limit of the temperature is not critical but should not be higher than the temperatures at which the various components become too volatile or disintegrate. Preferably, the upper limit does not exceed 200C and is more particularly at 150C because no additional advantages are to be obtained above the last mentioned temperature.
According to another preferred form of the inven-tion liquid benzoic acid is used for recovering caffeine from activated carbon. In view of the high melting point of benzoic acid, 122C. This agent gives hardly, if any, problems with respect to flammability or volatility, as is the case with acetic acid. Moreover, it has turned out that liquid benzoic acid is an excellent ~3~
extracting agent which permits to obtain very high extraction efficiencies, while the initial extraction is also very high, which is of special importance in continuous countercurrent methods.
It is a further advantage of benzoic acid that it is generally recognized as a safe product in food applications so that extracted carbon in which a slight amount of benzoic acid may still be present can be reused for decaffeinating coffee without causing probl~ms.
The process according to this preferred form should of course be carried out at temperatures at which benzoic acid is liquid. In view of the melting point of benzoic acid of 122C, temperatures ranging from 130 to 160C are preferred although higher or lower temperatures are also applicable, but lower temper-atures are not preferred because this involves the risk that benzoic acid will solidify in case of insuffi-cient heating, which results in the apparatus becoming clogged. Temperatures above 160C generally offer no advantages over temperatures below 160C, while there is also a risk that certain products will disinte~
grate.
In connection with the relatively low volatility of benzoic acid it is not necessary to operate under super atmospheric pressures. This is of course an advan-tage from the viewpoint of investments and energy consump-tion.
According to the lnvention ~e acid~ de~cribed are used ~s such or in admixture. If required, also mixtures with formic acid, acetic acid and/or propionic acid may be used. In general, th~ concentration of 5 the acid~ described i3 at least 50~ by weight, mor~
particularly they are used alone, that i~ to say th~
are not used with formic acid, acetic acid and/or propionic acid.
As indicated the treatment preferably takes oplace countercurrently, which leads to relatively short extraction times. The most appropriate extrac~ion times t and extraction amounts can be established by those skilled in the art by means of routine tests. The amount of extraction liquid per amount of activated carbon can be very small as a result of the highly efficient extraction, and in genera~, a fivefold to tenfold amount of extracting agent relative to the amount of loaded activated carbon will be sufficient. These amounts are considerably lower than the amounts required according 1 20to the state of the art, in which at least tenfold to twentyfold amounts are necessary. Of course, large amounts can also be used according to the invention, but this is not necessary. The caffeine-loaded carbon will generally originate from processes for removing 25caffeine from green coffee. Examples of such processes are described in European patent applications 40712 (December 2, 1981) 111375 (June 20, 1984) and 8398 (March 5, 1980).
i ........ , ~3~t~L7S~
After the caffeine has been removed Erom the carbon, it can be removed from the solution in the known manner, e.g. by means of crystallization.
After removal of the solvent and/or regeneration the carbon which is nearly completely liberated from caffeine can be reused for absorption of caffeine.
The invention also relates to a process for decaffeinating coffee by means of activated carbon, followed by recovery of the caffeine from the carbon, o which is characterized by treating the activated carbon using the process according to the invention.
The invention will be illustrated by some examples but is not restricted thereto.
Example I
A commercial activated carbon having a caffeine load of 44 g/kg carbon and a total dry load of 225 g/kg carbon was placed in a column heated to 120C, after which an amount dichloroacetic acid was pumped through the column from the top to the bottom at a 20 superficial velocity of 0.4 mm/sec.
After cooling the dichloroacetic acid was analyzed by means of HPLC as to caffeine content. Of the amount of caffeine present the carbon, 80.8% by weight was desorbed.
In EP 42295 a value of 73~ was found for the use of glacial acetic acid. It is therefore clear that a considerable improvement has been achieved by the ~3~7S~
invention.
Example II and comparative examp_ In the manner described in Example I tests were carried out with dichloroacetic acid and acetic acid at 112C. 100 g of the carbon was treated with the solvents, and a comparison was made between the caffeine contents in the first two fractions of ~5 ml. The results are listed in the table.
fraction acetic aci~ ~icillolo dCetiC ~ci~
caffeine conc.(g/l) caffeine conc.(g/l) l 16.3 26.6 2 13.8 17.5 These data clearly show that a superior initial extraction is obtained by the invention.
Comparative example Desorption by means of acetic acid.
In a 500 ml round-bottomed flask provided with reflux cooling, 100 g commercial carbon (81.7 g carbon) preloaded with caffeine and other components was desorbed by means of acetic acid. The desorption took place by repeatedly decanting the acetic acid, after which clean acetic acid was added again. The reElux time per charge was 30-40 minutes at 118C. The results are listed in table A.
Example III
Desorption by means of benzoic acid.
`` ~3~
g In a 500 ml round-bot-tomed flask provided with a stirrer, 100 g commercial (81.7 g carbon) carbon preloaded with caffeine and other components was desorbed by means of benzoic acid. The desorption took place by repeatedly decanting the benzoic acid melt, after which clean benzoic acid, in molten form, was added again. The stirring time per charge was 30-40 min.
at 150C. After cooling the fractions were analyzed for caffeine. The solubility of benzoic acid in water lo is only 2.9 g/kg. Then the amount of caffeine in the benzoic acid cannot be detected anymore. For the caffeine analysis in the benzoic acid samples, 1 g sample is weighed out and dissolved to 25 ml in acetic acid.
The caffeine content is determined in this solution.
lS The results are listed in Table B.
~3~L7S~
TABLE A
Solvent : Acetic acid Reflux temperature : 118C
Caffeine adsorption : 44 g/kg Caffeine desorption : 35.9 g/kg % Desorption/load : 81.6 %
Decanted Caf~elne CaffeineCaffeineCaffeine Volume volume concentr. absolute cumulativedesorbed cumulative (ml) (g/l) (g) (g) (%) (ml) 8.14 0.4477 0.447712.5 55 150 4.86 0.7290 1.176732.8 205 130 3.55 0.4615 1.638245.6 335 120 2.69 0.3228 1.961054.6 455 115 2.135 0.2455 2.206561.5 570 112 1.78 0.1994 2.405967.0 682 110 1.46 0.1606 2.566571.5 792 120 1.21 0.1452 2.711775.5 912 110 1.05 0.1155 2.~27278.7 1022 110 0.92 0.1012 2.928481.6 1132 ... . _ _ .. . _ _ _ B
~3~
TABLE B
Solvent : benzoic acid Temperature during stirring : 140 - 150C
Caffeine adsorption : 44 g/kg Caffeine desorption : 39.2 g/kg ~ Desorption/Adsorption : 89,1%
Decanted Caffeine Caffeine Caffeine Caffeine Weight weight concentr. absolute cumulative desorped Cumulative (g) (~) (g) (g) (%) (g) 68.5 1.86 1.274 1.274 35.568.5 130 0.827 1.075 2.349 65.4198.5 115 0.375 0.431 2.780 77.4313.5 84 0.217 0.182 2.962 82.5397.5 152 0.090 0.137 3.099 86.35~9.5 89 0.050 0.045 3.144 87.6638.5 84 0.035 0.029 3.174 88.4722.5 0.013 0.010 3.183 88.7797.5 107 0.010 0.011 3.193 88.9904.5 165 0.003 0.005 3.199 89.11069.5 B
~3~
The variation of the caffeine concentration as a function of the decanted amount of acid is graph-ically represented by Figs. 1 and 2. Fig. 3 graphically represents the percentage of desorbed caffeine as a function of the percentage of the decanted amount of acid in relation to the total amount of decanted acid (line a is acetic acid and line b benzoic acid).
Under the given process conditions the caffeine desorption effected with benzoic acid leads to better lo results than the desorption with acetic acid. For benzoic acid a desorption percentage of 89.1% was obtained.
For acetic acid this was 81.6%.
Example IV
100 g of a commercial activated carbon 15 having a caffeine load of 44 g/kg carbon (81.6 g unloaded carbon)Was desorbed with lactic acid (85-90%) in water by pumping 3 1 of this solution over a carbon column having a temperature of 100-105C (downflow) in about 4 hours. The eluentwascollectedin a number of fractions and analyzed for caffeine after cooling. The results are listed in the table.
~3`f~
TABLE C
Eluent : lactic acid (85-90%) Elution temperature : 110C at the double wall of the carbon column, 100-105C within -the column Caffeine desorption : 30. 38 g/kg Desorption efficiency : 70.08%
fraction rangevolume weight caff.conc. caffeine no. (ml) (ml) (g) (g /1 ) (g) 1 0 - 25 25.230.14 4.915 0.122 2 25 - 50 25.029.60 4.586 0.115 3 S0 - 100 39.546.78 4.119 0.163 4 100 - 200 90107.48 3.886 0.350 200 - 350 140166.17 2.216 0.310 6 350 - 500 140159.53 1.442 0.202 7 S00 - 1000 S00596.57 0.949 0.474 8 1000 - lS00 S00597.11 0.554 0.277 9 1500 - 2000 S00596.12 0.310 0.155 2000 - 2500 500596.24 0.256 0.128 11 2500 - 3000 412488.56 0.208 0.085 total 2911.83461.50 2.516 ~3V:17~
14~
Th~ result~ of thl~ te~t are ~hown in Fig.4.
Example V
Grean coffee was decaf~einated using the process described in European patent application 1113~5 (June 20, 1984).
Title: A process for recovering caffeine absorhed in activated carbon, and a process for decaffeinatin~ coffee.
This invention relates to a process for recovering caffeine from loaded activated carbon by traatment with an acid.
In the literature much has been published on the recovery of caffeine from caffeine-loaded activated carbon using solutions of acids. East German patent 7856~
relates to the recovery of caffeine from caffeine-loaded activated carbon using more concentrated acid than hitherto usual, giving rise to a clearly better extraction than the weakly acid solutions hitherto used. European patent application 42295 (December 23, 1981) relates to the use of glacial acetic acid as a means for removing caffeine from activated carbon.
European patent application 76620 (April 13, 1983) of the same applicants indicates that glacial acetic acid has the best effect indeed, but that for security reasons it is preferred to sacrifice a part of the efficiency and to use less concentrated acetic acid solutions.
Finally, European patent application 129609 (January 2, 1985) relates to the use of formic acid or mixtures of formic acid with a slight amount of water for recovering caffeine~
According to this last publication the use of formic ~3~ i4 acid leads to considerably better extraction results than the use of acetic acid. Formic acid, however, has a number of drawbacks, in particular the high volatil-ity.
The object of the present invention is to provide a process for recovering caffeine from caffeine-loaded activated carbon, which process gives a clearly better extraction efficiency than the hitherto known, above described means, while the rate of desorption is higher.
0 Other advantages of the invention will appear from the detailed discussion of the various preferred forms.
According to the invention the process for recover-ing caffeine from caffeine-loaded activated carbon is characterized by treating the activated carbon with 15 an acid having the formula H
Rl - C - COOH
wherein R1 is methyl, H or C1 and R2 is an electron-absorbing group.
Surprisingly, it has turned out that these acids alone, or in combination with each other or with other 20 acids give excellent results in the removal of caffeine from caffeine-loaded activated carbon. Preferably, this treatment takes place in a continuous countercurrent extraction.
According to a first preferred form the caffeine--25 loaded activated carbon is treated with mono- and/or dichloroacetic acicl.
In another preferred form the invention is charac-terized by treating the activated carbon with an acid having the above formula, wherein Rl is methyl or H
and R2 is OH.
Mono- and/or dichloroacetic acid, lactic acid but also glycolic acid have proved to be particularly suitable means for recovering caffeine from activated carbon, which means give no problems with respect to roastability or volatility. Besides, it has turned out that these are excellent extracting agents leading to very high extraction efficiencies while the initial extraction is also very high, which is of special impor-tance in continuous countercurrent methods. By a very high initial extraction is meant that upon contact of caffeine-free acid with loaded activated carbon a relatively large part of the caffeine present is nearly immediately released from the activated carbon.
It will be clear that this is advantageous to a continuous countercurrent extraction because this means that the activated carbon substantially released from caffeine is subjected to a very efficient final extraction.
Moreover, a number of these acids also originally occur in coffee. This means that it is not necessary ~s tothermally regenerate the treated carbon before reusing them.
It is observed that lactic acid occurs in two ~3~7~
isomeric forms. Whether D-lactic acid, L-lactic acid or a mixture thereof is used has no effect on the present invention. So for economical reasons a racemic mlxture is preferably used.
According to a specific preferred form the acids used according to the invention may be combined with other acids, such as formic acid, acetic acid and/of propionic acid.
The process according to the invention is prefer-lo ably carried out at a temperature of more than 100C
because an efficient extraction takes place at these temperatures. It is not necessary, however, to use superatmospheric pressures, which is of course a clear advantage. The upper limit of the temperature is not critical but should not be higher than the temperatures at which the various components become too volatile or disintegrate. Preferably, the upper limit does not exceed 200C and is more particularly at 150C because no additional advantages are to be obtained above the last mentioned temperature.
According to another preferred form of the inven-tion liquid benzoic acid is used for recovering caffeine from activated carbon. In view of the high melting point of benzoic acid, 122C. This agent gives hardly, if any, problems with respect to flammability or volatility, as is the case with acetic acid. Moreover, it has turned out that liquid benzoic acid is an excellent ~3~
extracting agent which permits to obtain very high extraction efficiencies, while the initial extraction is also very high, which is of special importance in continuous countercurrent methods.
It is a further advantage of benzoic acid that it is generally recognized as a safe product in food applications so that extracted carbon in which a slight amount of benzoic acid may still be present can be reused for decaffeinating coffee without causing probl~ms.
The process according to this preferred form should of course be carried out at temperatures at which benzoic acid is liquid. In view of the melting point of benzoic acid of 122C, temperatures ranging from 130 to 160C are preferred although higher or lower temperatures are also applicable, but lower temper-atures are not preferred because this involves the risk that benzoic acid will solidify in case of insuffi-cient heating, which results in the apparatus becoming clogged. Temperatures above 160C generally offer no advantages over temperatures below 160C, while there is also a risk that certain products will disinte~
grate.
In connection with the relatively low volatility of benzoic acid it is not necessary to operate under super atmospheric pressures. This is of course an advan-tage from the viewpoint of investments and energy consump-tion.
According to the lnvention ~e acid~ de~cribed are used ~s such or in admixture. If required, also mixtures with formic acid, acetic acid and/or propionic acid may be used. In general, th~ concentration of 5 the acid~ described i3 at least 50~ by weight, mor~
particularly they are used alone, that i~ to say th~
are not used with formic acid, acetic acid and/or propionic acid.
As indicated the treatment preferably takes oplace countercurrently, which leads to relatively short extraction times. The most appropriate extrac~ion times t and extraction amounts can be established by those skilled in the art by means of routine tests. The amount of extraction liquid per amount of activated carbon can be very small as a result of the highly efficient extraction, and in genera~, a fivefold to tenfold amount of extracting agent relative to the amount of loaded activated carbon will be sufficient. These amounts are considerably lower than the amounts required according 1 20to the state of the art, in which at least tenfold to twentyfold amounts are necessary. Of course, large amounts can also be used according to the invention, but this is not necessary. The caffeine-loaded carbon will generally originate from processes for removing 25caffeine from green coffee. Examples of such processes are described in European patent applications 40712 (December 2, 1981) 111375 (June 20, 1984) and 8398 (March 5, 1980).
i ........ , ~3~t~L7S~
After the caffeine has been removed Erom the carbon, it can be removed from the solution in the known manner, e.g. by means of crystallization.
After removal of the solvent and/or regeneration the carbon which is nearly completely liberated from caffeine can be reused for absorption of caffeine.
The invention also relates to a process for decaffeinating coffee by means of activated carbon, followed by recovery of the caffeine from the carbon, o which is characterized by treating the activated carbon using the process according to the invention.
The invention will be illustrated by some examples but is not restricted thereto.
Example I
A commercial activated carbon having a caffeine load of 44 g/kg carbon and a total dry load of 225 g/kg carbon was placed in a column heated to 120C, after which an amount dichloroacetic acid was pumped through the column from the top to the bottom at a 20 superficial velocity of 0.4 mm/sec.
After cooling the dichloroacetic acid was analyzed by means of HPLC as to caffeine content. Of the amount of caffeine present the carbon, 80.8% by weight was desorbed.
In EP 42295 a value of 73~ was found for the use of glacial acetic acid. It is therefore clear that a considerable improvement has been achieved by the ~3~7S~
invention.
Example II and comparative examp_ In the manner described in Example I tests were carried out with dichloroacetic acid and acetic acid at 112C. 100 g of the carbon was treated with the solvents, and a comparison was made between the caffeine contents in the first two fractions of ~5 ml. The results are listed in the table.
fraction acetic aci~ ~icillolo dCetiC ~ci~
caffeine conc.(g/l) caffeine conc.(g/l) l 16.3 26.6 2 13.8 17.5 These data clearly show that a superior initial extraction is obtained by the invention.
Comparative example Desorption by means of acetic acid.
In a 500 ml round-bottomed flask provided with reflux cooling, 100 g commercial carbon (81.7 g carbon) preloaded with caffeine and other components was desorbed by means of acetic acid. The desorption took place by repeatedly decanting the acetic acid, after which clean acetic acid was added again. The reElux time per charge was 30-40 minutes at 118C. The results are listed in table A.
Example III
Desorption by means of benzoic acid.
`` ~3~
g In a 500 ml round-bot-tomed flask provided with a stirrer, 100 g commercial (81.7 g carbon) carbon preloaded with caffeine and other components was desorbed by means of benzoic acid. The desorption took place by repeatedly decanting the benzoic acid melt, after which clean benzoic acid, in molten form, was added again. The stirring time per charge was 30-40 min.
at 150C. After cooling the fractions were analyzed for caffeine. The solubility of benzoic acid in water lo is only 2.9 g/kg. Then the amount of caffeine in the benzoic acid cannot be detected anymore. For the caffeine analysis in the benzoic acid samples, 1 g sample is weighed out and dissolved to 25 ml in acetic acid.
The caffeine content is determined in this solution.
lS The results are listed in Table B.
~3~L7S~
TABLE A
Solvent : Acetic acid Reflux temperature : 118C
Caffeine adsorption : 44 g/kg Caffeine desorption : 35.9 g/kg % Desorption/load : 81.6 %
Decanted Caf~elne CaffeineCaffeineCaffeine Volume volume concentr. absolute cumulativedesorbed cumulative (ml) (g/l) (g) (g) (%) (ml) 8.14 0.4477 0.447712.5 55 150 4.86 0.7290 1.176732.8 205 130 3.55 0.4615 1.638245.6 335 120 2.69 0.3228 1.961054.6 455 115 2.135 0.2455 2.206561.5 570 112 1.78 0.1994 2.405967.0 682 110 1.46 0.1606 2.566571.5 792 120 1.21 0.1452 2.711775.5 912 110 1.05 0.1155 2.~27278.7 1022 110 0.92 0.1012 2.928481.6 1132 ... . _ _ .. . _ _ _ B
~3~
TABLE B
Solvent : benzoic acid Temperature during stirring : 140 - 150C
Caffeine adsorption : 44 g/kg Caffeine desorption : 39.2 g/kg ~ Desorption/Adsorption : 89,1%
Decanted Caffeine Caffeine Caffeine Caffeine Weight weight concentr. absolute cumulative desorped Cumulative (g) (~) (g) (g) (%) (g) 68.5 1.86 1.274 1.274 35.568.5 130 0.827 1.075 2.349 65.4198.5 115 0.375 0.431 2.780 77.4313.5 84 0.217 0.182 2.962 82.5397.5 152 0.090 0.137 3.099 86.35~9.5 89 0.050 0.045 3.144 87.6638.5 84 0.035 0.029 3.174 88.4722.5 0.013 0.010 3.183 88.7797.5 107 0.010 0.011 3.193 88.9904.5 165 0.003 0.005 3.199 89.11069.5 B
~3~
The variation of the caffeine concentration as a function of the decanted amount of acid is graph-ically represented by Figs. 1 and 2. Fig. 3 graphically represents the percentage of desorbed caffeine as a function of the percentage of the decanted amount of acid in relation to the total amount of decanted acid (line a is acetic acid and line b benzoic acid).
Under the given process conditions the caffeine desorption effected with benzoic acid leads to better lo results than the desorption with acetic acid. For benzoic acid a desorption percentage of 89.1% was obtained.
For acetic acid this was 81.6%.
Example IV
100 g of a commercial activated carbon 15 having a caffeine load of 44 g/kg carbon (81.6 g unloaded carbon)Was desorbed with lactic acid (85-90%) in water by pumping 3 1 of this solution over a carbon column having a temperature of 100-105C (downflow) in about 4 hours. The eluentwascollectedin a number of fractions and analyzed for caffeine after cooling. The results are listed in the table.
~3`f~
TABLE C
Eluent : lactic acid (85-90%) Elution temperature : 110C at the double wall of the carbon column, 100-105C within -the column Caffeine desorption : 30. 38 g/kg Desorption efficiency : 70.08%
fraction rangevolume weight caff.conc. caffeine no. (ml) (ml) (g) (g /1 ) (g) 1 0 - 25 25.230.14 4.915 0.122 2 25 - 50 25.029.60 4.586 0.115 3 S0 - 100 39.546.78 4.119 0.163 4 100 - 200 90107.48 3.886 0.350 200 - 350 140166.17 2.216 0.310 6 350 - 500 140159.53 1.442 0.202 7 S00 - 1000 S00596.57 0.949 0.474 8 1000 - lS00 S00597.11 0.554 0.277 9 1500 - 2000 S00596.12 0.310 0.155 2000 - 2500 500596.24 0.256 0.128 11 2500 - 3000 412488.56 0.208 0.085 total 2911.83461.50 2.516 ~3V:17~
14~
Th~ result~ of thl~ te~t are ~hown in Fig.4.
Example V
Grean coffee was decaf~einated using the process described in European patent application 1113~5 (June 20, 1984).
5 The caffeine loaded activated carbon was then subjected to a countercurrent treatment wi~h a go% colution of lactlc acid in water. Good yields were obtained.
Claims (10)
1. A process for recovering caffeine from caffeine-loaded activated carbon by liquid extraction of said activated carbon with an acid selected from benzoic acid or, a compound having the formula wherein R1 is methyl, H or Cl, and R2 is Cl, OH or phenyl.
2. A process as claimed in claim 1, wherein R1 is methyl, and R2 is OH.
3. A process as claimed in claim 1, wherein R1 is H.
4. A process as claimed in claim 1, wherein R1 and R2 are both Cl.
5. A process as claimed in claim 1, wherein the liquid extraction is a countercurrent extraction.
6. A process as claimed in claim 1, wherein the extraction is carried out at a temperature of more than 100°C.
7. A process as claimed in claim 3, wherein the acid is benzoic acid.
8. A process as claimed in claim 7, wherein the extraction is carried out at a temperature of at least 130°C.
9. A process as claimed in claims 7 or 8, wherein the extraction is carried out at a temperature of not more than 160°C.
10. A process as claimed in claim 1, wherein the caffeine extracted is recovered by crystallization.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL8601400 | 1986-05-30 | ||
| NL8601401 | 1986-05-30 | ||
| NL8601400A NL8601400A (en) | 1986-05-30 | 1986-05-30 | PROCESS FOR THE COLLECTION OF CAFFEINE ABSORBED FROM ACTIVE CARBON. |
| NL8601401A NL8601401A (en) | 1986-05-30 | 1986-05-30 | Decaffeination of green coffee - by treating aq. extract with activated carbon, regenerating carbon with acid, and recycling washed carbon |
| NL8601783 | 1986-07-08 | ||
| NL8601783A NL8601783A (en) | 1986-07-08 | 1986-07-08 | Decaffeination of green coffee - by treating aq. extract with activated carbon, regenerating carbon with acid, and recycling washed carbon |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1301754C true CA1301754C (en) | 1992-05-26 |
Family
ID=27352144
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000538013A Expired - Lifetime CA1301754C (en) | 1986-05-30 | 1987-05-26 | Process for recovering caffeine absorbed in activated carbon, and a process for decaffeinating coffee |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4877631A (en) |
| EP (1) | EP0251364B1 (en) |
| AU (1) | AU598544B2 (en) |
| CA (1) | CA1301754C (en) |
| DE (1) | DE3765189D1 (en) |
| DK (1) | DK275287A (en) |
| ES (1) | ES2018008B3 (en) |
| NO (1) | NO165193C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1301754C (en) * | 1986-05-30 | 1992-05-26 | Louris Kaper | Process for recovering caffeine absorbed in activated carbon, and a process for decaffeinating coffee |
| DE3806372A1 (en) * | 1988-02-24 | 1989-08-31 | Code Kaffee Handel | METHOD FOR SEPARATING AND DETERMINING COFFEINE FROM RAW COFFEE AND FOR DETERMINING DECAFFINATED COFFEE |
| ES2136067T3 (en) * | 1992-08-18 | 1999-11-16 | Kraft Jacobs Suchard Ag | PROCEDURE FOR THE EXTRACTION OF CAFFEINE FROM ACTIVATED CARBON. |
| ES2127784T3 (en) * | 1993-02-24 | 1999-05-01 | Sara Lee De Nv | SIMULTANEOUS REGENERATION OF CAFFEINE AND ACTIVE CARBON WHICH IS ADsorbed BY ORGANIC SOLVENTS. |
| US20230383068A1 (en) * | 2022-05-24 | 2023-11-30 | Microban Products Company | Composition and method for microbial control for use with polymers |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DD78586A (en) * | ||||
| CA1083880A (en) * | 1975-06-24 | 1980-08-19 | Gary L. Hickernell | Method for decaffeinating green coffee |
| US4495210A (en) * | 1980-05-28 | 1985-01-22 | Societe D'assistance Technique Pour Produits Nestle S.A. | Caffeine adsorption |
| US4298736A (en) * | 1980-06-16 | 1981-11-03 | General Foods Corporation | Carbon-caffeine separation |
| ES512478A0 (en) * | 1981-09-28 | 1983-03-01 | Gen Foods Corp | "IMPROVEMENTS INTRODUCED IN THE PURPOSE OF MAIN PATENT N 503.050, REQUESTED ON JUNE 15, 1981, BY: A PROCEDURE TO RECOVER CAFFEINE FROM ACTIVATED CARBON". |
| US4548827A (en) * | 1982-03-30 | 1985-10-22 | General Foods Corporation | Separate recovery of caffeine and coffee solids adsorbed on activated carbon |
| US4443601A (en) * | 1982-09-20 | 1984-04-17 | General Foods Corporation | Recovery of caffeine from caffeine adsorbents |
| NL188074C (en) * | 1982-12-10 | 1992-04-01 | Douwe Egberts Tabaksfab | METHOD FOR DECAFFINING GREEN COFFEE BEANS WITH ACTIVE COBOL. |
| US4540784A (en) * | 1983-04-18 | 1985-09-10 | Hag Gf Aktiengesellschaft | Recovery of caffeine adsorbed to activated carbon |
| CA1301754C (en) * | 1986-05-30 | 1992-05-26 | Louris Kaper | Process for recovering caffeine absorbed in activated carbon, and a process for decaffeinating coffee |
| CA1318811C (en) * | 1986-05-30 | 1993-06-08 | Louris Kaper | Process for decaffeinating green coffee |
| NL8602012A (en) * | 1986-08-06 | 1988-03-01 | Douwe Egberts Tabaksfab | PROCESS FOR EXTRACTING CAFFEINE ADSORBED TO ACTIVE CARBON. |
-
1987
- 1987-05-26 CA CA000538013A patent/CA1301754C/en not_active Expired - Lifetime
- 1987-05-27 EP EP87200996A patent/EP0251364B1/en not_active Expired - Lifetime
- 1987-05-27 ES ES87200996T patent/ES2018008B3/en not_active Expired - Lifetime
- 1987-05-27 DE DE8787200996T patent/DE3765189D1/en not_active Expired - Lifetime
- 1987-05-29 AU AU73634/87A patent/AU598544B2/en not_active Ceased
- 1987-05-29 DK DK275287A patent/DK275287A/en unknown
- 1987-05-29 NO NO872256A patent/NO165193C/en unknown
- 1987-06-01 US US07/055,850 patent/US4877631A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| AU7363487A (en) | 1987-12-03 |
| EP0251364B1 (en) | 1990-09-26 |
| NO165193C (en) | 1991-01-09 |
| DE3765189D1 (en) | 1990-10-31 |
| DK275287D0 (en) | 1987-05-29 |
| NO872256D0 (en) | 1987-05-29 |
| US4877631A (en) | 1989-10-31 |
| AU598544B2 (en) | 1990-06-28 |
| EP0251364A1 (en) | 1988-01-07 |
| DK275287A (en) | 1987-12-01 |
| ES2018008B3 (en) | 1991-03-16 |
| NO165193B (en) | 1990-10-01 |
| NO872256L (en) | 1987-12-01 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |